On the hunt for a new ampere While there's been lots of attention paid to the search for a new kilogram, another of the SI system's fundamental units of measurement is under examination: the ampere. Along with the kilogram, metre, second, Kelvin, mole and candela, the ampere is one of the fundamental yardsticks used to measure the world around us. And, …
We already have standard and metric tonnes, imperial, dry, and liquid pints and gallons, liters (or litres), miles and KPH to contend with. Will we have 20 metric-amp circuit breakers in our homes soon? I'm going to get a few pints of beer of some sort now... whichever measurement is more volume...
Can the reg come up with its own unit of measurement for electric current? Such as how many badgers you have to rub against a glass rod to produce enough current to light a 100W lamp?
"No, Eddy, what I am saying is that we continue to learn about how the universe works, at a higher & higher resolution."
Really? Looked more like "I'll be a supercilious twat because I was getting into electronics/IT years before all of you (honest.)"
"This is a good thing."
No, it isn't.
Presumably you missed the bit where the value differs depending on how you measure it? Since that is a problem there therefore must be no good or valid way to determine which value to choose. Not to mention if it is wrong then other calculations using much more tightly defined units will have the accuracy of the result degraded by the Coulomb.
Which is why they are trying to do it properly instead.
What is it with trying to re-define the kilogram? Every sane person knows it's 2.2 pounds, so what's all the fuss about? If the damned frogs would just get with the program already and quit fussing around, we could get some serious work done, but no, it's all "kilo this" and "meter that." I mean, who the hell decided we needed a smaller unit of measure, which would be approximately 0.3937 inches? How the hell are reasonable people supposed to remember this drivel? Now we have wings that don't fit the airplanes they were built for, and spacecraft that miss their targets, all because some frogs can't figure out how to convert their dark-ages base-10 system into Real Units. Give me an inch and I'll take a mile, but leave the damn meters out of it unless we're talking cab fare.
" I mean, who the hell decided we needed a smaller unit of measure, which would be approximately 0.3937 inches? "
Yep. Why would anyone want to measure anything to an accuracy greater then a furlong, perch , rod, bushel, chain, acre ? I mean come on now, why would you ? What good would it be ? What could you use it for ?
It was good enough for Grandad. Irony, isn't that a measure of how much iron is in a comment ?
Heaven forbid we try to make logical set of units that can be easily calculated in the head, and at the same time try to (other than the kilogram) define them exactly using universal constants.
That sounds terrible! Why don't we stick with a useless old mess?
That said, you can still use old units in informal settings, it's not like (as the Daily Mail would have you believe) someone from Brussels breaks down your door and takes you away for describing your DIY handwork in inches.
Petrol sold in litres, road signs in miles. The uk never really 'got' the metric system. (These days I wonder what they're talking about when top gear insists on using horsepower, gallons, yards etc. The imperial system is so much an exercise in memory that few people bother memorizing any of it. How many yards in a mile? oh and Irish miles are different than english ones aren't they? Who knows how powerful a horse is anyway? Equestrians? What sort of horse? etc. but top gear and their fans love to hate anything French almost as much as I love to hate Clarkson)
P.s I am British and was taught metric from the beginning. actually school kids have been taught metric for 40 years, so there is understandable dissonance when the so called 'grown ups' continue to use the jumble of anti-mnemonic base 16 base 12 base whatever except 10 system.
....Who knows how powerful a horse is anyway? Equestrians? What sort of horse? etc. but top gear and their fans love to hate anything French.....
Yes of course. Top Gear should use the continental system, in which a car's output is measured in "PS". This stands for "pferdestärke", which is german for, er, "horsepower".....
It's a lot.
The current devices (no pun intended) would take 1 x 10^13 secs to count that many electrons, the new hotness could knock that down by a factor of 10 000, which would still mean it takes about a year to run (roughly pi giga seconds in a year).
Thumbs up for upping the frequency of these little critters by a factor of 10 000.
Which in most other industries would be considered quite impressive.
Well it's electrons per second. So the speed you can count at limits the highest current you can measure. Additionally it's a bit hard to "scale" currents so it's hard to divide a current by a well defined factor.
Of course all of that is just theologic by definition since Metrology is just about the belief of something called "Reality" which can be explored by "measurements".
but I can't wait to see the little surprises when they try to compare those amp-meters devices in different labs. It's some decades now that they try to redefine the kg based on a well-define number of atoms and what sounded like a simple concept some decade ago became horribly complex and still doesn't work. Let's hope this one is different.
All I can say is GTF! Clearly the way we do things now is so terrible that buildings fall down because the measurements they use to build them are not accurate enough, and millions of electronic devices are blowing up left right and centre because the components used to build them are not rated tightly enough.....
What a joke - how much exactly are these new new (since we already have new) units of measurement a) costing to standardise and b) costing to integrate?
The speed and distance signs in the UK are what they are because it would simply cost far too much to change them...
I shall assume this is EU sticking it's fat wrinkly nose in again to further make life difficult for this country - because they come up with such fantastic ideas that make no sense (like the Cookie Law) which no-one else in EU bothers to implement - just the UK - at great expense.... (like the battery hens law)
The footnote gives the modern definition of the ampere in terms of its magnetic effect. When I was a lad, the ampere was defined in terms of its electroplating effect; viz: That quantity of current which is capable of depositing 62.10 grains of silver per hour from a silver nitrate solution.
@Andrew Jones 2
"The speed and distance signs in the UK are what they are because it would simply cost far too much to change them..."
Well, they did it in Eire!
"Distance signs had displayed kilometres since the 1990s but road speed limits were in miles per hour until January 2005, when they were finally changed to kilometres per hour. "
I suppose your logic would argue that changing the road signs was the direct cause of the financial crisis in Eire?
There are several things going on here.
i) the Irish government has generally been pretty good at running a balanced budget (the recent austerity measures being due to taking on massive debt all at once to pay for nationalising banks and guaranteeing deposits) so paying for a few new road signs wouldn't be a big deal
ii) Ireland is pretty small compared to the UK
iii) it could have been a move to differentiate RoI from NI (though at least Ireland still drives on the correct side of the road)
iv) arguably the Irish system of distances in km and speed limits in mph was barmy and needed to be changed one way or the other.
v) why change the signs? they don't really cause the UK any problems. So long as they are consistent, who cares? There are lots of other things to worry about.
Perhaps, you might want to reconsider as there is not one damn thing wrong with the Amp just the way it is. Perhaps those who want to diddle around with miniscule values might just realize that measurements that small don't have any redeeming value in how "accurate" they are compared to one another.
Quit frikking around whith shite that does not provide any benefit. This is another case of Schroedingers twat.
The point of all this "diddling around with miniscule values" is that the inaccuracies are problematic for those using more cutting edge technology -- the present definition is simply not good enough. Any redefinitions will indeed be so small in relative terms (much less than parts per million) that the change would have no effect on most applications.
It won't affect my work, as we run a 'third tier' electrical calibration lab where our uncertainties are orders of magnitude higher than the probable corrections -- higher level labs may have to account for a redefinition to maintain their relative uncertainty levels, however.
Just because something is a useless exercise to you or I in our mundane activities does not mean it is a worthless exercise for everyone.
Well perhaps there is though...
Didn't you see the video of the boy and his atom? So, there we are looking at tiny, tiny things bopping about... And the boys in blue are telling us this is going to have something to do with storage, as if we needed telling that.
And their boffins are going...okay so how many amps do we need for these devices...and one of them says, well how much is an amp these days...like in comparison to these tiny, tiny things we made that terrible prawn flick of...oh, well let's see, an amp is like all those balls in that cool ad with the song by yer man on his guitar...heartbeats?...that's the one, anyway that many fer a second like...ah, could you be a bit more specific?...Eh, we'll have to ask Dan Paul, he says there's no point...NOT EVEN FOR SCIENCE!
C18,
Science simply for the sake of science is in many cases, an incredible waste of resources.
Changing units of measurement that are frankly quite good enough for what they are used for (simply because you can) is extraordinarily stupid. AND a huge waste of resources...
I suggest a new unit for such people, the microfuckwit. a unit of measurement that not only defines the unit but the person using it.
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